I once had someone like your BIL sitting behind me on a plane. I was flying back to the UK for a funeral on a Friday evening commuter flight. A man in the row behind spent the entire hour (which seemed considerably longer at the time) telling his neighbour all about how wonderful he was and detailling all the amazing things he'd done and the fantastic places he'd been. You name it, he'd been there/done that/been given an award for best t-shirt design. To cap it all, he had the most boring, monotonous voice I have ever had the misfortune of hearing in real life. Remember the Father Ted episode where a priest with a boring voice makes an announcement over the shop PA system to create a diversion so that they can all escape from the lingerie department? This man's voice was worse than that.
It had been a long day, an even longer week and, unfortunately, I had recently been watching The Thick of It on DVD, which always throws my swear-o-metre off kilter.
After what seemed like an eternity, the pilot came over the intercom and said that we were starting our descent, at which point the man behind me said "already? well, listen to me talking all the way through the flight. I don't know why I did that, I don't usually sit around telling my life story to strangers on a plane."
Readers, to this day, I cannot explain exactly what came over me at this point. I blame a combination of tiredness, grief and the large G&T I'd had during the flight. I let out a sigh and said, loudly and clearly
"well shut the fuck up then you boring cunt"
DH went bright red and stuck his elbow into my ribs. The man on the other side of me burst out laughing, gave me a small round of applause and said "thank you! I've been dying to say that myself for the last 50 minutes". Later on, as we were leaving the airport, I saw him laughing again as he pointed me out to a woman who had apparently been waiting for him. Boring man didn't say another word for the rest of the flight and scuttled off as soon as they opened the plane doors. The man who had been sitting next to him gave me a wink and a thumbs up sign at the luggage carrousel.
I promise I'm not usually that rude not outloud anyway but I have to admit, it felt good.